Fix #195 as suggested by @oripka

Author: andrawaag

setup.py

@@ -1,6 +1,6 @@
 from setuptools import setup, find_packages
 
-VERSION = "0.9.22"
+VERSION = "0.9.23"
 
 setup(
     name='wikidataintegrator',

wikidataintegrator/wdi_core.py

@@ -128,7 +128,7 @@ def execute_sparql_query(query, prefix=None, endpoint=None, user_agent=None, as_
                 continue
             if response.status_code == 429:
                 if "retry-after" in response.headers.keys():
-                    retry_after = response.headers["retry-after"]
+                    retry_after = int(response.headers["retry-after"])
                 print("service unavailable. sleeping for {} seconds".format(retry_after))
                 time.sleep(retry_after)
                 continue